例句：
有人曾經(jīng)認(rèn)為鉛可以變成黃金。
It was once thought that lead could be transmuted into gold.
人們?cè)?jīng)認(rèn)為地球是平的。
People used to think the earth was flat.
我曾經(jīng)在倫敦居住過。
I used to live in London.
2024-10-23
例句：
有人曾經(jīng)認(rèn)為鉛可以變成黃金。
It was once thought that lead could be transmuted into gold.
人們?cè)?jīng)認(rèn)為地球是平的。
People used to think the earth was flat.
我曾經(jīng)在倫敦居住過。
I used to live in London.